Heretofore, in various electric apparatuses and electronic apparatuses, in order to absorb extraordinary high voltage, elimination of noise, elimination of arc, and the like, SiC baristors or varistors of ZnO system having a voltage-dependent non-linear resistance characteristics are used. Voltage-current characteristic of such baristors can be approximately represented by the following equation: EQU I=(V/C).sup..alpha.,
wherein I is current, V is voltage, C is a constant proper for the baristor, and .alpha. is a voltage non-linearity exponent.
The .alpha. of the SiC baristor is about 2-7, and for the ZnO system baristor there is ones that reaching 50. Though such baristors has superior characteristic for absorbing relatively high voltage called surge, for voltages lower than baristor voltage (for instance, absorption of noise) almost no effect is represented since its dielectric constant is low and its inherent capacitance is small, and their dielectric loss angle tan .delta. are so large as 5-10%.
On the other hand, for elimination of low voltage noise, static electricity, or the like, by appropriately selecting composition and firing condition, semiconductor ceramic capacitors having apparent dielectric constant of about 5.times.10.sup.4 -6.times.10.sup.4 and tan .delta. of about 1% are utilized.
However, these semiconductor ceramic capacitor is liable to be destroyed or become to be non-functional as capacitors when extraordinary high voltage such as surge is impressed thereon or a current above a certain limit is impressed on the element. For such reason, in the electric apparatuses or electronic apparatuses, for the purpose of both the absorbing of high voltage surge and the elimination of low voltage noise, the baristors are used being combined with capacitors and other component (for instance, coil), and for instance, a noise filter has such configuration.
FIG. 1 shows general noise filter circuit, FIG. 2 shows conventional noise filter circuit constituted by combining a baristor, capacitors and a coil, and 1 is the coil, 2 are the capacitors and 3 is the baristor.
When a noise input A shown in FIG. 5 is impressed on these circuits, output characteristic from general noise filter circuit of FIG. 1 is such as C of FIG. 5, and noise is not eliminated sufficiently. Output characteristic from the conventional noise filter circuit including a baristor shown in FIG. 2 is such as B of FIG. 5, and though noise is eliminated, such configuration has a shortcoming that it has large number of components in the inside of the apparatus and besides is contrary to tendency of miniaturization of the apparatus.
Accordingly, an electronic component, which absorbs extraordinary high voltage, can eliminate low voltage, such as noise and has small number of components, and capable of miniaturization, is demanded.